scholarly journals A Proposal of a Troposphere Model in a GNSS Simulator for VANET Applications

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2491
Author(s):  
Mauro Tropea ◽  
Angelo Arieta ◽  
Floriano De Rango ◽  
Francesco Pupo

Vehicle positioning is becoming an important issue related to Intelligent Transportation Systems (ITSs). Novel vehicles and autonomous vehicles need to be localized under different weather conditions and it is important to have a reliable positioning system to track vehicles. Satellite navigation systems can be a key technology in providing global coverage and providing localization services through many satellite constellations such as GPS, GLONASS, Galileo and so forth. However, the modeling of positioning and localization systems under different weather conditions is not a trivial objective especially considering different factors such as receiver sensitivity, dynamic weather conditions, propagation delay and so forth. This paper focuses on the use of simulators for performing different kinds of tests on Global Navigation Satellite System (GNSS) systems in order to reduce the cost of the positioning testing under different techniques or models. Simulation driven approach, combined with some specific hardware equipment such as receivers and transmitters can characterize a more realistic scenario and the simulation can consider other aspects that could be complex to really test. In this work, the main contribution is the introduction of the Troposphere Collins model in a GNSS simulator for VANET applications, the GPS-SDR-SIM software. The use of the Collins model in the simulator allows to improve the accuracy of the simulation experiments throughout the reduction of the receiver errors.

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3800 ◽  
Author(s):  
Daehee Kim ◽  
Jeongho Cho

The reliability of a navigation system is crucial for navigation purposes, especially in areas where stringent performance is required, such as civil aviation or intelligent transportation systems (ITSs). Therefore, integrity monitoring is an inseparable part of safety-critical navigation applications. The receiver autonomous integrity monitor (RAIM) has been used with the global navigation satellite system (GNSS) to provide integrity monitoring within avionics itself, such as in civil aviation for lateral navigation (LNAV) or the non-precision approach (NPA). However, standard RAIM may not meet the stricter aviation availability and integrity requirements for certain operations, e.g., precision approach flight phases, and also is not sufficient for on-ground vehicle integrity monitoring of several specific ITS applications. One possible way to more clearly distinguish anomalies in observed GNSS signals is to take advantage of time-delayed neural networks (TDNNs) to estimate useful information about the faulty characteristics, rather than simply using RAIM alone. Based on the performance evaluation, it was determined that this method can reliably detect flaws in navigation satellites significantly faster than RAIM alone, and it was confirmed that TDNN-based integrity monitoring using RAIM is an encouraging alternative to improve the integrity assurance level of RAIM in terms of GNSS anomaly detection.


2018 ◽  
Vol 34 ◽  
pp. 01019
Author(s):  
Khin Cho Myint ◽  
Abd Nasir Matori ◽  
Adel Gohari

Global Navigation Satellite System (GNSS) has become a powerful tool for high-precision deformation monitoring application. Monitoring of deformation and subsidence of offshore platform due to factors such as shallow gas phenomena. GNSS is the technical interoperability and compatibility between various satellite navigation systems such as modernized GPS, Galileo, reconstructed GLONASS to be used by civilian users. It has been known that excessive deformation affects platform structurally, causing loss of production and affects the efficiency of the machinery on board the platform. GNSS have been proven to be one of the most precise positioning methods where by users can get accuracy to the nearest centimeter of a given position from carrier phase measurement processing of GPS signals. This research is aimed at using GNSS technique, which is one of the most standard methods to monitor the deformation of offshore platforms. Therefore, station modeling, which accounts for the spatial correlated errors, and hence speeds up the ambiguity resolution process is employed. It was found that GNSS combines the high accuracy of the results monitoring the offshore platforms deformation with the possibility of survey.


2020 ◽  
Vol 961 (7) ◽  
pp. 8-13
Author(s):  
V.V. Scherbakov ◽  
A.P. Karpik ◽  
I.V. Scherbakov ◽  
M.N. Barsuk ◽  
I.A. Buntsev

The development of a monitoring system based on global satellite navigation systems (GNSS) of ballast compaction quality during the construction and overhaul of railways is covered in the article. Traditional geodetic methods for determining the quality of ballast compaction are tedious. Non-geodetic methods (dynamic control systems, empirical models and geophysical methods) are not widely used on railways due to the low reliability of the ballast compaction quality, as well as the high complexity of the work. The proposed method and device of a quality control system for ballast compaction are based on the measurement of draft and residual deformations during compaction in dynamic mode. The current coordinates are determined using GNSS with dual-antenna positioning receivers performing advanced functions, including determining the relative position of the antennas in plan and height. The monitoring system developed at the Siberian State University of Railway Engineering enables real-time determining parameters which characterize the quality of compaction with high accuracy and the ability of controlling the compaction process according to the current parameters.


2014 ◽  
Vol 7 (6) ◽  
pp. 735-745 ◽  
Author(s):  
S. Irteza ◽  
E. Schäfer ◽  
R. Stephan ◽  
A. Hornbostel ◽  
M. A. Hein

A compact navigation receiver comprising a decoupled and matched four-element L1-band antenna array with an inter-element separation of a quarter of the free-space wavelength is presented in this paper. We investigate the impact of the decoupling and matching network on the robustness of the navigation receiver. It is observed that in order to achieve high robustness with a compact antenna array, it is necessary to employ a decoupling and matching network, particularly in case of three spatially separated interferers. Furthermore, we study the influence of the polarization impurity of the compact planar antenna array on the equivalent carrier-to-interference-plus-noise ratio (CINR) of the receiver when impinged with different numbers of diametrically polarized interference signals. It is shown that the higher-order modes possess strong polarization impurity, which may halve the available degrees-of-freedom for nulling in the presence of linear-polarized interferers, using a conventional null-steering algorithm. We verify the robustness of the designed compact receiver by means of a complete global-navigation-satellite-system demonstrator. It is shown that the maximum jammer power that is allowed us to maintain the CINR above 38 dBHz with three interferers can be improved by more than 10 dB if a decoupling and matching network is employed.


2014 ◽  
Vol 915-916 ◽  
pp. 1189-1193 ◽  
Author(s):  
Lei Du ◽  
Nan Liu ◽  
Rui Fang ◽  
Xiang Hui Song

Cooperative positioning (CP) is one of the core features in intelligent transportation systems (ITS) which is used to increase the positioning accuracy via wireless communication between vehicles and infrastructures. The global navigation satellite system (GNSS) is always unavailable near black spot such as the curve which needs to be solved. So, in this paper, a novel CP scheme is proposed for the curve warning scenario with limited GNSS by utilizing the information of received signal strength and pointer angular of the roadside unit which is in a special dual-transmitter outphasing architecture. An extended Kalman filter is founded to estimate the real-time position of the vehicle in the curve section. The whole warning scenario is analyzed by computer simulation, and the result shows the feasibility of the method.


2010 ◽  
Vol 63 (4) ◽  
pp. 681-693 ◽  
Author(s):  
Shengyue Ji ◽  
Wu Chen ◽  
Xiaoli Ding ◽  
Yongqi Chen ◽  
Chunmei Zhao ◽  
...  

With the existing GPS, the replenishment of GLONASS and the launching of Galileo there will be three satellite navigation systems in the future, with a total of more than 80 satellites. So it can be expected that the performance of the global navigation satellite system (GNSS) will be greatly improved, especially in urban environments. This paper studies the potential benefits of GPS/GLONASS/Galileo integration in an urban canyon – Hong Kong. The navigation performances of four choices (GPS alone, GPS+GLONASS, GPS+Galileo and GPS+GLONASS+Galileo) are evaluated in terms of availability, coverage, and continuity based on simulation. The results show that there are significant improvements in availability, coverage and continuity, by using GPS+GLONASS+Galileo compared with the other choices. But the performance is still not good enough for most navigation applications in urban environments.


2014 ◽  
Vol 21 (1) ◽  
pp. 117-132 ◽  
Author(s):  
Paweł Przestrzelski ◽  
Mieczysław Bakuła

AbstractThis paper presents the essential issues and problems associated with GNSS (Global Navigation Satellite System) code differential positioning simultaneously using observations from at least two independent satellite navigation systems. To this end, two satellite navigation systems were selected: GPS (Global Positioning System, USA) and GLONASS (GLObalnaya NAvigatsionnaya Sputnikovaya Sistema, Russia). The major limitations and methods of their elimination are described, as well as the basic advantages and benefits resulting from the application of the DGNSS (Differential GNSS) positioning method. Theoretical considerations were verified with the post-processed observations gathered during a six-hour measurement. The data from selected reference stations of the ASG-EUPOS (Active Geodetic Network — EUPOS) system located at different distances from the rover site was used. The study showed that the DGNSS positioning method achieves higher accuracy and precision, and improves the stability of coordinate determination in the time domain, compared to positioning which uses only one satellite navigation system. However, it was shown that its navigational application requires further studies, especially for long distances from the reference station.


Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5149 ◽  
Author(s):  
Bingbing Gao ◽  
Gaoge Hu ◽  
Xinhe Zhu ◽  
Yongmin Zhong

INS/GNSS (inertial navigation system/global navigation satellite system) integration is a promising solution of vehicle navigation for intelligent transportation systems. However, the observation of GNSS inevitably involves uncertainty due to the vulnerability to signal blockage in many urban/suburban areas, leading to the degraded navigation performance for INS/GNSS integration. This paper develops a novel robust CKF with scaling factor by combining the emerging cubature Kalman filter (CKF) with the concept of Mahalanobis distance criterion to address the above problem involved in nonlinear INS/GNSS integration. It establishes a theory of abnormal observations identification using the Mahalanobis distance criterion. Subsequently, a robust factor (scaling factor), which is calculated via the Mahalanobis distance criterion, is introduced into the standard CKF to inflate the observation noise covariance, resulting in a decreased filtering gain in the presence of abnormal observations. The proposed robust CKF can effectively resist the influence of abnormal observations on navigation solution and thus improves the robustness of CKF for vehicular INS/GNSS integration. Simulation and experimental results have demonstrated the effectiveness of the proposed robust CKF for vehicular navigation with INS/GNSS integration.


2014 ◽  
Vol 945-949 ◽  
pp. 3255-3259 ◽  
Author(s):  
Lei Du ◽  
Nan Liu ◽  
Rui Fang ◽  
Nan Li ◽  
Xiang Hui Song

Cooperative positioning (CP) originating in wireless sensor networks (WSN) is expected to enhance the accuracy of real-time positioning by exchanging location related information in vehicular network via wireless communication. A novel CP system based on beam-forming for vehicular networks is proposed by this work. Its application includes several roadside units equipped with a kind of transceiver based on an special dual-transmitter outphasing architecture which are utilized to broadcast the spatial directivity and correct receive angle information to vehicles with onboard wireless communication units in desired areas. The goal of enhancement positioning via vehicle-to-infrastructure communication can be acquired by a data fusion means based on the extended Kalman filter when GNSS is available and a cooperative solution based on the least-squares method under the condition that the global navigation satellite system (GNSS) is available respectively. The main process of positioning and all the key technical points of the system's application are modeled and analyzed mathematically. And the results of computer simulation confirm the technical practicability for the proposed method.


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